To investigate the effect of N-acetylcysteine(NAC)on cognitive function and nuclear factor erythroid 2 related factor 2/ heme oxygenase-1(Nrf2/HO-1)pathway in mouse models of postoperative cognitive dysfunction. Methods Fifty-four male C57BL/6J mice(3-4 months old)were randomly divided into control group,surgery group,and surgery+NAC group by block randomization.The intramedullary fixation for left tibial fracture surgery was performed to establish postoperative cognitive dysfunction models.NAC(150 mg/kg)was administered intraperitoneally in group surgery+NAC 30 minutes before and 3 hours,6 hours after surgery,while saline was given in control group and surgery group.Six mice in each group were selected randomly underwent Morris water maze test on the third day after surgery.Animals were sacrificed at the first and third postoperative days,and the hippocampus was harvested.Enzyme-linked immunosorbent assay was used to quantify the levels of interleukin-6(IL-6)and malondialdehyde(MDA)in hippocampus.Western blot and real-time polymerase chain reaction were used to measure the expressions of Nrf2 and HO-1 in hippocampus. Results There was no significant difference in swimming speed among three groups(=2.135,=0.114).Compared with control group and surgery+NAC group,the surgery group had prolonged escape latency(<0.01),reduced platform crossing times(<0.01),and shortened time spent in the target quadrant(<0.01).Compared with the control group,the surgery group and the surgery+NAC group had significantly increased levels of IL-6 and MDA in hippocampus at the first postoperative day(all =0.000).On the third postoperative day,there was no significant difference in the levels of IL-6(=0.251)and MDA(=0.103)between control group and surgery+NAC group.The protein expressions of Nrf2 and HO-1 in hippocampus were significantly higher in surgery group and surgery+NAC group than in control group and significantly higher in surgery+NAC group than in surgery group(all =0.000).The mRNA expressions of Nrf2 and HO-1 in hippocampus were significantly higher in surgery group and surgery+NAC group than in control group and significantly higher in surgery+NAC group than in surgery group (all =0.000). Conclusions NAC pretreatment may reduce oxidative stress and inflammatory response in hippocampus and improve cognitive function.Such effect may be relate to the activation of Nrf2/HO-1 pathway.
Acetylcysteine ; pharmacology ; Animals ; Cognition ; drug effects ; Cognitive Dysfunction ; drug therapy ; etiology ; Heme Oxygenase-1 ; metabolism ; Male ; Membrane Proteins ; metabolism ; Mice ; Mice, Inbred C57BL ; NF-E2-Related Factor 2 ; metabolism ; Postoperative Complications ; Random Allocation

Objective To evaluate the antagonistic effects of N-acetylcysteine (NAC) on mitogen-activated protein kinases (MAPK) pathway activation, oxidative stress and inflammatory responses in rats with lung injury induced by fine particulate matter (PM_2.5). Methods Forty eight male Wistar rats were randomly divided into six groups: blank control group (C1), water drip control group (C2), PM_2.5 exposed group (P), low-dose NAC treated and PM_2.5 exposed group (L), middle-dose NAC treated and PM_2.5 exposed group (M), and high-dose NAC treated and PM_2.5 exposed group (H). PM_2.5 suspension (7.5 mg/kg) was administered tracheally once a week for four times. NAC of 125 mg/kg, 250 mg/kg and 500 mg/kg was delivered intragastrically to L, M and H group respectively by gavage (10 ml/kg) for six days before PM_2.5 exposure. The histopathological changes and human mucin 5 subtype AC (MUC5AC) content in lung tissue of rats were evaluated. We investigated IL-6 in serum and bronchoalveolar lavage fluid (BALF) by Enzyme-linked immunosorbent assay (ELISA), MUC5AC in lung tissue homogenate by ELISA, glutathione peroxidase (GSH-PX) in serum and BALF by spectrophotometry, and the expression of p-ERK1/2, p-JNK1/2 and p-p38 proteins by Western blot. All the measurements were analyzed and compared statistically. Results Lung tissue of rats exposed to PM_2.5 showed histological destruction and increased mucus secretion of bronchial epithelial cells. Rats receiving NAC treatment showed less histological destruction and mucus secretion. Of P, L, M and H group, MUC5AC in lung tissue, IL-6 in serum and BALF were higher than controls (C1 and C2) (all P<0.05), with the highest levels found in the P group and a decreasing trend with increase of NAC dose. The activity of GSH-PX in serum and BALF of PM_2.5 exposed rats (P, L, M and H) was lower than that of controls (all P<0.05), with higher activities found in NAC treated rats (L, M, and H), and an increasing trend with increase of NAC dose. The expressions of p-ERK1/2, p-JNK1/2 and p-p38 proteins in PM_2.5 exposed lung tissue (P, L, M and H) was higher than controls (all P<0.05), with decreased levels and dose dependent downregulation found in NAC treated rats. Conclusion NAC can antagonize major MAPK pathway activation, lung oxidative stress and inflammatory injury induced by PM_2.5 in rats.
Acetylcysteine/pharmacology* ; Animals ; Bronchoalveolar Lavage Fluid ; Enzyme Activation/drug effects* ; Glutathione Peroxidase/metabolism* ; Inflammation/pathology* ; Interleukin-6/metabolism* ; Lung/pathology* ; Lung Injury/pathology* ; Male ; Mitogen-Activated Protein Kinases/metabolism* ; Mucin 5AC/metabolism* ; Mucus/metabolism* ; Oxidative Stress/drug effects* ; Particle Size ; Particulate Matter/toxicity* ; Phosphorylation/drug effects* ; Rats, Wistar

This study investigated the effects of N-acetylcysteine (NAC) and ascorbic acid (AA) on hemin-induced K562 cell erythroid differentiation and the role of reactive oxygen species (ROS) in this process. Hemin increased ROS levels in a concentration-dependent manner, whereas NAC and AA had opposite effects. Both NAC and AA eliminated transient increased ROS levels after hemin treatment, inhibited hemin-induced hemoglobin synthesis, and decreased mRNA expression levels of β-globin, γ-globin, and GATA-1 genes significantly. Pretreatment with 5,000 μmol/L AA for 2 h resulted in a considerably lower inhibition ratio of hemoglobin synthesis than that when pretreated for 24 h, whereas the ROS levels were the lowest when treated with 5,000 μmol/L AA for 2 h. These results show that NAC and AA might inhibit hemin-induced K562 cell erythroid differentiation by downregulating ROS levels.
Acetylcysteine ; pharmacology ; Antioxidants ; pharmacology ; Ascorbic Acid ; pharmacology ; Cell Differentiation ; drug effects ; Down-Regulation ; Erythroid Cells ; drug effects ; Hemin ; pharmacology ; Humans ; K562 Cells ; Reactive Oxygen Species ; metabolism

Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B (Cuc B) is a natural triterpenoid with potent anticancer activities while its effect on metastasis remains unclear. In the present study, the inhibitory effect and mechanisms of Cuc B on metastasis were investigated in MDA-MB-231 breast cancer cells. The cells were treated with or without Cuc B, and the cytotoxicity was determined by MTT assay. The effect of Cuc B on metastasis was evaluated with wound healing, transwell, and adhesion assays. Furthermore, the adhesion of cancer cells to endothelial cells was determined. The protein expression was determined by Western blotting. Cuc B (< 100 nmol·L) showed no obvious cytotoxicity to MDA-MB-231 cells, but significantly inhibited migration, invasion, and adhesion to Matrigel, fibronectin, type I collagen, and endothelial cells. Cuc B dramatically inhibited the phosphorylation of focal adhesion kinase (FAK) and paxillin in dose- and time-dependent manners. Furthermore, Cuc B induced intracellular reactive oxygen species (ROS) generation, which could be reduced by N-acetyl-l-cysteine (NAC). In addition, NAC pretreatment could reverse Cuc B-induced suppression of migration and adhesion, expression of FAK, but showed no effect on paxillin expression. In summary, Cuc B suppressed ROS-dependent metastasis through FAK pathway in breast cancer MDA-MB-231 cells, demonstrating novel mechanisms for the anticancer effects of Cuc B.
Acetylcysteine ; pharmacology ; Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; enzymology ; metabolism ; pathology ; physiopathology ; Cell Adhesion ; drug effects ; Cell Line, Tumor ; Cell Movement ; drug effects ; Collagen Type I ; metabolism ; Dose-Response Relationship, Drug ; Down-Regulation ; drug effects ; Female ; Fibronectins ; metabolism ; Focal Adhesion Kinase 1 ; metabolism ; Humans ; Neoplasm Invasiveness ; pathology ; Neoplasm Metastasis ; pathology ; Paxillin ; metabolism ; Phosphorylation ; drug effects ; Reactive Oxygen Species ; metabolism ; Triterpenes ; antagonists & inhibitors ; chemistry ; pharmacology

OBJECTIVEThe aim of this study is to investigate hepatic and renal toxicity of acrylamide (ACR) , the antagonistic effect and possible mechanism of N-acetylcysteine (NAC) on the toxicity.

METHODSForty female SD rats were randomly divided into four groups. All the rats were administrated by intraperitoneal(i.p.) injection and 1.5 hours later by gavage. The control group was administrated with 0.9% NaCl by i.p. injection and gavaged with 0.9% NaCl. The NAC group was administrated with 200 mg/kg NAC by injection and gavaged with 0.9% NaCl. The ACR group was administrated with 0.9% NaCl by injection and gavaged with 40 mg/kg ACR. The combined treatment group was administrated with 200 mg/kg NAC by i.p. injection and gavaged with 40 mg/kg ACR. The rats were administrated once a day for 2 weeks. After 24 hours of the last administration, the rats were decapitated. The blood was collected, the liver and kidney were separated. The body weight, organ coefficient and serum biochemical parameters were measured, and the pathological changes of the tissues were examined with a microscope. Then the expression of NF-κB p65, IκB-α and COX-2 were detected by Western blot.

RESULTSFrom the second day to the end of the exposure, the body weight of rats in the ACR group was statistically lower than that in the control group (P<0.05) . Compared with the combined treatment group, the body weight in the ACR group statistically decreased in the second and third days (P < 0.05) . The liver and kidney organ coefficients in the ACR group were (4.159%±.371%) and (0.764%±0.068%) respectively, which increased statistically when compared with the control group (P < 0.05) . The contents of ALT, AST and Cr in the serum in the ACR group were (77.370±16.397) U/L、(379.410±57.817) U/L and (77.812±6.391) μmol/L respectively, which were not significantly different with those in the control group and the combined treatment group (P>0.05) . The content of BUN in the serum in the ACR group was (7.005±1.009) mmol/L, which was statistically higher than that in the control group (P<0.05) . Histopathology results showed unclear boundary and nucleus pyknosis in hepatocytes, loose and disordered structures of hepatic cords in the ACR group, but no obvious pathology changes were observed in the kidneys of each group. In the Western blot results, the expression of nuclear NF-κB p65 and COX-2 in the liver in the ACR group was statistically higher than that in the control group and the combined treatment group (P<0.05) , and the expression of IκB-α in the liver in the ACR group statistically decreased compared with the control group and the combined treatment group (P<0.05) . The expression of total NF-κB p65 in the liver in the ACR group was statistically higher than that in the control group (P<0.05) .

CONCLUSIONUnder the conditions of this experiment, ACR may induce hepatic toxicity through the activation of NF-κB signaling pathway, and NAC could antagonize the hepatic toxicity of ACR by inhibiting the NF-κB signaling pathway, whereas the toxic effect of ACR on kidney needs to be further studied.

Acetylcysteine ; pharmacology ; Acrylamide ; toxicity ; Animals ; Cyclooxygenase 2 ; metabolism ; Female ; I-kappa B Proteins ; metabolism ; Kidney ; drug effects ; metabolism ; pathology ; Liver ; drug effects ; metabolism ; NF-KappaB Inhibitor alpha ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Transcription Factor RelA ; metabolism

Nitrites play multiple characteristic functions in invasion and metastasis of hepatic cancer cells, but the exact mechanism is not yet known. Cancer cells can maintain the malignant characteristics via clearance of excess mitochondria by mitophagy. The purpose of this article was to determine the roles of nitrite, reactive oxygen species (ROS) and hypoxia inducing factor 1 alpha (HIF-1 α) in mitophagy of hepatic cancer cells. After exposure of human hepatocellular carcinoma SMMC-7721 cells to a serial concentrations of sodium nitrite for 24 h under normal oxygen, the maximal cell vitality was increased by 16 mg x (-1) sodium nitrite. In addition, the potentials of migration and invasion for SMMC-7721 cells were increased significantly at the same time. Furthermore, sodium nitrite exposure displayed an increase of stress fibers, lamellipodum and perinuclear mitochondrial distribution by cell staining with Actin-Tracker Green and Mito-Tracker Red, which was reversed by N-acetylcysteine (NAC, a reactive oxygen scavenger). DCFH-DA staining with fluorescent microscopy showed that the intracellular level of ROS concentration was increased by the sodium nitrite treatment. LC3 immunostaining and Western blot results showed that sodium nitrite enhanced cell autophagy flux. Under the transmission electron microscopy (TEM), more autolysosomes formed after sodium nitrite treatment and NAC could prevent autophagosome degradation. RT-PCR results indicated that the expression levels of COX I and COXIV mRNA were decreased significantly after sodium nitrite treatment. Meanwhile, laser scanning confocal microscopy showed that sodium nitrite significantly reduced mitochondrial mass detected by Mito-Tracker Green staining. The expression levels of HIF-1α, Beclin-1 and Bnip3 (mitophagy marker molecular) increased remarkably after sodium nitrite treatment, which were reversed by NAC. Our results demonstrated that sodium nitrite (16 mg x L(-1)) increased the potentials of invasion and migration of hepatic cancer SMMC-7721 cells through induction of ROS and HIF-1α mediated mitophagy.
Acetylcysteine ; pharmacology ; Autophagy ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Movement ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Liver Neoplasms ; pathology ; Mitochondrial Degradation ; Neoplasm Invasiveness ; Nitrites ; metabolism ; Reactive Oxygen Species ; metabolism ; Sodium Nitrite ; pharmacology

OBJECTIVETo evaluate the effect of palmitic acid (PA) on oxidative stress and activation of inflammasomes in hepatocytes.

METHODSTo test the dose-dependent effect of PA on normal murine hepatocytes AML12, the cells were treated with 0, 0.15, 0.25 and 0.4 mmol/L of palmitic acid (PA). The cells were also divided into blank control group, 0.25 mmol/L PA group and 0.25 mmol/L PA+N-acetylcysteine (NAC) group to examine the effect of reactive oxygen species (ROS) on the activation of inflammasomes. After 24 h of treatment, lipid accumulation, total ROS, mitochondrial ROS, expression and localization of NOX4, and expressions of inflammasomes and IL-1β were detected in the hepatocytes.

RESULTSCompared with the control cells, PA treatment of the cells significantly increased cytoplasmic lipid accumulation, concentrations of total ROS (12 463.09±2.72 vs 6691.23±2.45, P=0.00) and mitochondrial ROS (64.98±0.94 vs 45.04±0.92, P=0.00), and the expressions of NOX4, NLRP3, ASC, caspase-1, and IL-1β (1603.52±1.32 vs 2629.33±2.57, P=0.00). The mitochondria and NOX4 were found to be co-localized in the cytoplasm. NAC obviously reduced cellular ROS level stimulated by PA (7782.15±2.87 vs 5445.6±1.17, P=0.00) and suppressed the expressions of NLRP3, ASC and caspase-1.

CONCLUSIONPA treatment can stimulate lipid accumulation in hepatocytes and induce oxidative stress through NOX4 and mitochondria pathway to activate inflammasomes and stimulate the secretion of IL-1β.

Acetylcysteine ; pharmacology ; Animals ; Carrier Proteins ; metabolism ; Caspase 1 ; metabolism ; Cells, Cultured ; Hepatocytes ; drug effects ; metabolism ; Inflammasomes ; drug effects ; metabolism ; Interleukin-1beta ; metabolism ; Mice ; Mitochondria ; drug effects ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; Oxidative Stress ; Palmitic Acid ; pharmacology ; Reactive Oxygen Species ; metabolism

BACKGROUND: Real-time reverse transcription PCR (rRT-PCR) of sputum samples is commonly used to diagnose Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Owing to the difficulty of extracting RNA from sputum containing mucus, sputum homogenization is desirable prior to nucleic acid isolation. We determined optimal homogenization methods for isolating viral nucleic acids from sputum. METHODS: We evaluated the following three sputum-homogenization methods: proteinase K and DNase I (PK-DNase) treatment, phosphate-buffered saline (PBS) treatment, and N-acetyl-L-cysteine and sodium citrate (NALC) treatment. Sputum samples were spiked with inactivated MERS-CoV culture isolates. RNA was extracted from pretreated, spiked samples using the easyMAG system (bioMérieux, France). Extracted RNAs were then subjected to rRT-PCR for MERS-CoV diagnosis (DiaPlex Q MERS-coronavirus, SolGent, Korea). RESULTS: While analyzing 15 spiked sputum samples prepared in technical duplicate, false-negative results were obtained with five (16.7%) and four samples (13.3%), respectively, by using the PBS and NALC methods. The range of threshold cycle (Ct) values observed when detecting upE in sputum samples was 31.1-35.4 with the PK-DNase method, 34.7-39.0 with the PBS method, and 33.9-38.6 with the NALC method. Compared with the control, which were prepared by adding a one-tenth volume of 1:1,000 diluted viral culture to PBS solution, the ranges of Ct values obtained by the PBS and NALC methods differed significantly from the mean control Ct of 33.2 (both P<0.0001). CONCLUSIONS: The PK-DNase method is suitable for homogenizing sputum samples prior to RNA extraction.
Acetylcysteine/chemistry ; Citrates/chemistry ; Coronavirus Infections/diagnosis ; Deoxyribonuclease I/metabolism ; Endopeptidase K/metabolism ; Humans ; Middle East Respiratory Syndrome Coronavirus/genetics/*isolation & purification ; RNA, Viral/analysis/*isolation & purification/metabolism ; Real-Time Polymerase Chain Reaction ; Sputum/*virology

OBJECTIVETo investigate the effects of extremely low frequency electromagnetic field (ELF-EMF) on human osteosarcoma cells and its mechanisms.

METHODSHuman osteosarcoma MG-63 cells were exposed to 50 Hz,1 mT ELF-EMF for 1, 2 and 3 h in vitro, with or without pretreatment by reactive oxygen species (ROS) inhibitor N acetylcysteine (NAC) or p38MAPK inhibitor SB203580. The proliferation of MG-63 cells was determined by MTT method; the apoptosis rate and ROS level in MG-63 cells were detected by flow cytometry. The expression of p38MAPK in MG-63 cells was determined by Western blotting.

RESULTSELF-EMF decreased the viability of MG-63 cells, inhibited cell growth, induced cell apoptosis and increased the level of ROS significantly. The apoptosis rate declined significantly after treatment with ROS inhibitor NAC or p38MAPK inhibitor SB203580. After exposure to ELF-EMF, p38MAPK in MG-63 cells was activated, and the phosphorylation level was also inhibited after treatment with NAC.

CONCLUSIONELF-EMF can induce the apoptosis of MG-63 cells. Increased ROS and p38MAPK activation may be involved in the mechanism.

Acetylcysteine ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Electromagnetic Fields ; Humans ; Imidazoles ; Osteosarcoma ; pathology ; Oxidative Stress ; Phosphorylation ; Pyridines ; Reactive Oxygen Species ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo compare the effects of oral treatment with tetrandrine (TD) and N-acetylcys-teine (NAC) separately or jointly on silica-exposed rats.

METHODS40 sprague-Dawly (SD) rats were randomly divided into normal saline group, quartz group, TD treatment group (50 mg/kg), NAC treatment group (500 mg/kg) and combined treatment group (TD: 50 mg/kg + NAC: 500 mg/kg). Rats in normal saline group and other groups received intratracheal instillation of normal saline and quartz dust suspension respectively. Treatment groups were given TD, NAC separately or jointly via esophagus the next day after instillation, once a day and six times a week for 30 consecutive days. At the end of experiment, the pathological changes of lung tissues were evaluated by the methods of Foot, HE and Masson staining, the level of hydroxyproline (HYP), malondjalde-hyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lung tissues were measured by alkaline hydrolysis method, the barbituric acid method and enzyme-linked immunosorbent assay (ELISA) respectively.

RESULTSCompared with the quartz group, lymph nodes/body coefficients in all treatment groups and lung/body coefficient in combined treatment group were significantly decreased (P < 0.05). Pathology results showed that the normal saline group demonstrated no obvious evidence of lung damage. The quartz group lungs silicotic lesions focused on II~III level, the TD treatment group was mainly with I level, the NAC treatment group was mainly with I~II level, and the combined treatment group only showed little silicotic nodule, no obvious fibrosis. HYP content in TD treatment group and combined treatment group were significantly lower than that in the quartz group (P < 0.05), while it showed no obvious change in NAC treatment group. MDA content in lung tissues of each treatment group (TD treatment group, NAC treatment group and combined treatment group) were 18.80 ± 2.94, 20.13 ± 4.01 and 17.05 ± 3.52 nmol/ml respectively, which lower than in the quartz group (23.99 ± 3.26 nmol/ml). The level of IL-6 in lung tissues of the quartz group were 89.57 ± 8.78 pg/ml. After TD and NAC monotherapy, the IL-6 content decreased to 79.22 ± 9.65 pg/ml and 81.63 ± 5.72 pg/ml, and it decreased more significantly after combined medication (74.37 ± 3.17 pg/ml). The level of TNF-α in the quartz group were 59.05 ± 4.48 pg/ml. After TD and NAC monotherapy, the TNF-α content decreased to 50.48 ± 2.76 pg/ml and 54.28 ± 4.30 pg/ml, and it decreased more significantly after combined medication (49.10 ± 4.98 pg/ml).

CONCLUSIONNAC and TD could reduce MDA, TNF-α and IL-6 levels in lung tissue, and alleviate SiO2-induced pulmonary fibrosis in rats. Combined treatment with TD and NAC was more effective than TD or NAC treatment separately.

Acetylcysteine ; pharmacology ; Animals ; Benzylisoquinolines ; pharmacology ; Disease Models, Animal ; Dust ; Hydroxyproline ; metabolism ; Interleukin-6 ; metabolism ; Lung ; pathology ; Malondialdehyde ; metabolism ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; Quartz ; toxicity ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Silicosis ; drug therapy ; Tumor Necrosis Factor-alpha ; metabolism